Question : Hardware Interrupt and CPU

I have an XP machine SP 2 that I have recently cleaned for viruses. This particular one disabled task manager, which I had never seen before. I am using process explorer from sysinternals and find that there is a "Interrupts" process that is using about 50% of the CPU. The weird thing is that it does not show up in task manager not to mention the fact the the system idle time is near 100% while this process is eating about 50%. The hard drive also appears to have frequent activity as well. I am at a loss of what to try next. Please help! Thanks!

Answer : Hardware Interrupt and CPU

While it could be something different, this problem on one of the systems I fixed was due to the disk controller reverting from DMA to PIO mode.  The fix was to go into device manager and remove the "primary ide channel" and the "secondary ide channel" and then reboot.  Windows should auto-detect the hardware again and reset it correctly.

See screen shot attached.